#include "apue.h"

#define BUFFSIZE 4096

int main()
{
    int n;
    char buf[BUFFSIZE];

    while ((n = read(STDIN_FILENO, buf, BUFFSIZE)) > 0)
    {
        if ((write(STDOUT_FILENO, buf, n)) != n)
            err_sys("write error");
    }

    if (n < 0)
        err_sys("read error");
    
    return 0;
}